Mechanisms of neuropathogenesis in HIV and HCV: similarities, differences, and unknowns

Is there a connection between neurocognitive profile in treatment naïve non-cirrhotic HCV patients and level of systemic inflammation?

Hepatitis C virus (HCV) infection is a progressive, systemic disease which leads to the development of end-stage liver disease. In 70% of patients, HCV infection is followed by the development of extrahepatic manifestations (EHM). A common EHM is HCV associated neurocognitive disorder (HCV-AND), characterized by neuropsychological changes in attention, working memory, psychomotor speed, executive function, verbal learning, and recall. The aim of this study is to examine the correlation between the neurocognitive profile and routine, available laboratory parameters of inflammation, liver function tests, grade of liver fibrosis, and clinical and laboratory parameters of mixed cryoglobulinemia in treatment naïve non-cirrhotic HCV patients. This is a single-center exploratory study in which we examined 38 HCV + treatment naïve patients. The complete blood count and hematological parameters of systemic inflammation, liver function tests, biopsy confirmed grade of liver fibrosis, and clinical and laboratory parameters of mixed cryoglobulinemia caused by chronic HCV infection were observed. In the study, we used a battery of neuropsychological tests assessing multiple cognitive domains: executive functions, verbal fluency, delayed memory, working memory and learning, and one measure for visuo-constructive performance. Before the Bonferroni correction for multiple comparisons, the results show significant correlations between the scores in the neurocognitive variables and the single measures of inflammation, liver function parameters, and mixed cryoglobulinemia. It has not found a statistically significant correlation between systemic inflammation and neurocognitive variables. After the Bonferroni adjustment, no correlations remained significant. Certainly, the obtained results can be a recommendation for additional validation through future research.

Alzheimer's disease as a viral disease: Revisiting the infectious hypothesis

Alzheimer's disease (AD) represents the most frequent type of dementia in elderly people. Two major forms of the disease exist: sporadic - the causes of which have not yet been fully understood - and familial - inherited within families from generation to generation, with a clear autosomal dominant transmission of mutations in Presenilin 1 (PSEN1), 2 (PSEN2) or Amyloid Precursors Protein (APP) genes. The main hallmark of AD consists of extracellular deposits of amyloid-beta (Aβ) peptide and intracellular deposits of the hyperphosphorylated form of the tau protein. An ever-growing body of research supports the viral infectious hypothesis of sporadic forms of AD. In particular, it has been shown that several herpes viruses (i.e., HHV-1, HHV-2, HHV-3 or varicella zoster virus, HHV-4 or Epstein Barr virus, HHV-5 or cytomegalovirus, HHV-6A and B, HHV-7), flaviviruses (i.e., Zika virus, Dengue fever virus, Japanese encephalitis virus) as well as Human Immunodeficiency Virus (HIV), hepatitis viruses (HAV, HBV, HCV, HDV, HEV), SARS-CoV2, Ljungan virus (LV), Influenza A virus and Borna disease virus, could increase the risk of AD. Here, we summarized and discussed these results. Based on these findings, significant issues for future studies are also put forward.

Low levels of peripheral blood activated and senescent T cells characterize people with HIV-1-associated neurocognitive disorders

Background

HIV infection induces a 75% increase in the risk of developing neurocognitive impairment (NCI), which has been linked to immune activation. We therefore looked for immune activation markers correlating with NCI.

Method

Sixty-five people aged 55-70 years living with controlled HIV-1 infection were enrolled in the study and their neurocognitive ability was assessed according to the Frascati criteria. Fifty-nine markers of T4 cell, T8 cell, NK cell, and monocyte activation, inflammation and endothelial activation were measured in their peripheral blood. White matter hyperintensities (WMH) were identified by magnetic resonance imaging. Double hierarchical clustering was performed for the activation markers and 240 patients including the 65 whose neurocognitive performance had been evaluated.

Results

Thirty-eight percent of volunteers presented NCI. Twenty-four percent of them were asymptomatic and fourteen percent had a mild disorder. Strikingly, activated (HLA-DR+) as well as senescent (CD57+CD28-CD27±) T4 cells and T8 cells were less prevalent in the peripheral blood of participants with NCI than in participants without the disorder. Accordingly, the percentage of HLA-DR+ T4 cells was lower in volunteers with periventricular and deep WMH. The double hierarchical clustering unveiled six different immune activation profiles. The neurocognitive performances of participants with two of these six profiles were poor. Here again, these two profiles were characterized by a low level of T4 and T8 cell activation and senescence.

Conclusion

Our observation of low circulating levels of activated and senescent T cells in HIV-1 patients with NCI raises the interesting hypothesis that these lymphocytes may be recruited into the central nervous system.

Improvement of chronic HCV infection-related depression, anxiety, and neurocognitive performance in persons achieving SVR-12: A real-world cohort study

Chronic hepatitis C virus (HCV) infection is associated with neuropsychiatric changes. Also, patients with cirrhosis may develop overt or minimal hepatic encephalopathy. Sustained virological response (SVR) with direct-acting antiviral agents (DAAs) may improve the neuropsychiatric manifestations and quality of life (QoL). Consecutive patients (with and without cirrhosis, all genders and aged 18-65 years) with hepatitis C were assessed at enrolment and at 12 weeks after therapy completion for mood (Beck's Depression Inventory [BDI]), anxiety (generalized anxiety disorder [GAD-7]), QoL (SF-36 ver.2) and computer-based tests for number connection (NCT), visual memory, Stroop test and reaction times. We recruited 385 viraemic chronic HCV patients (76.1% male, 21.0% cirrhotic, mean age 39.4 ± 14.2 years, 59.3% genotype 3, mean HCV RNA load 5.8 log). Overall SVR-12 rates were 90.6%, with cure rates 87.6% and 91.4% in patients with and without cirrhosis, respectively. Patients who achieved SVR-12 had mean percentage reduction in BDI (11.3%, p = .000), GAD (8.6%, p = .001) and Stroop test (58.4%, p = .001), with improved NCT (1.7%, p = .001), visual memory (13.7%, p = .001) and digit span (23.8%, p = .002). On multivariate logistic regression, adherence (OR, 17.5 [95% CI 2.80-110.50], p = .000), high ALT (OR 1.02 [95% CI 1.00-1.05]), and BDI score (OR 1.73 [95% CI 1.42-3.26] p = .039) predicted cure. SVR-12 was associated with improved visual memory ≥5.5 (AUC-0.708; sensitivity 62.5%, specificity 63%, p = .000) and % correct Stroop test responses >26.6% (AUC-0.918, sensitivity 94.4% specificity 80.4%, p = .000). In conclusion, given the cumulative evidence of the safety of DAAs and efficacy of improving cognitive and neuropsychological and quality-of-life outcomes irrespective of age and gender, as shown in our study, future recommendations should focus on integrated universal HCV care to enable HCV elimination.

Neuropsychological effects of direct-acting antiviral treatment for Hepatitis C virus subjects: A systematic review

Direct-acting antivirals (DAAs) have been approved in recent years to treat patients infected by the Hepatitis C virus (HCV). The DAAs treatment is well tolerated and increases sustained virological responses, but there is no consensus about the neuropsychological functioning related to the treatment. This systematic review aims to provide an overview of the recent findings exploring the cognitive effects of DAAs treatment in patients with HCV. After a systematic search on PubMed, Embase, Scopus and LILACS, studies that assessed neuropsychological data related to DAAs treatment were included. We found nine articles, considering the inclusion and exclusion criteria. Three other manuscripts were included after searching for the references listed in the previously mentioned articles. We observed methodological heterogeneity in terms of neuropsychological tests used, cognitive domain explored and the sample characteristic presented between the studies. Studies presented data from HCV subjects monoinfected with or without cirrhosis, advanced liver disease and post-transplant patients; and HCV subjects coinfected with human immunodeficiency virus (HIV). Most results from the 12 studies that explored the effect of DAAs treatment in HCV subjects' neurocognitive functioning demonstrated cognitive improvement following treatment. In general, HCV and HCV/HIV subjects improved processing speed, verbal fluency and verbal/visual episodic memory. The DAAs treatment is effective for neurocognitive functioning in HCV monoinfected and coinfected subjects, with or without advanced liver disease, since neuropsychological scores increased after treatment. Further studies, however, are needed to confirm these findings.